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I see a lot of posts about the subject of using heated hoses with humidifiers. I could find nothing about the idea of leaving tube heat on while turning the humidifier off (no water in the reservoir). It would seem that even without heated water, the slight warming of the ambient air from the hose alone might be beneficial. Any thoughts? Anyone?

Not recommended.
The heated hose prevents rainout, but needs moisture to work at all.
When my tank runs dry, it gets stinky.

lawrencetate1 wrote: ↑

Wed Nov 23, 2022 11:34 am

I see a lot of posts about the subject of using heated hoses with humidifiers. I could find nothing about the idea of leaving tube heat on while turning the humidifier off (no water in the reservoir). It would seem that even without heated water, the slight warming of the ambient air from the hose alone might be beneficial. Any thoughts? Anyone?

Which brand and model machine?
Some will let you use the heated hose function with no water or heat to humidifier and some won't.

Warming the air with no increase in the absolute moisture content results in a decrease in relative humidity. In other words you've made the air more drying by heating it.

lawrencetate1 wrote: ↑

Wed Nov 23, 2022 11:34 am

I see a lot of posts about the subject of using heated hoses with humidifiers. I could find nothing about the idea of leaving tube heat on while turning the humidifier off (no water in the reservoir). It would seem that even without heated water, the slight warming of the ambient air from the hose alone might be beneficial. Any thoughts? Anyone?

turning the humidifier off (no water in the reservoir)

That does not turn the humidifier off.

chunkyfrog wrote: ↑

Wed Nov 23, 2022 12:27 pm

When my tank runs dry, it gets stinky.

So does mine.
However, I happen to have tried what you're aiming for in the last week with a ResMed AutoSense 10.
No heat to the humidifier, - and no water in the humidifier, and no problem.

How to get there:
Set climateline to manual
Set the hose temp to whatever you want -
Set the humidifier to "Off" by turning the nob all the way down, counter clockwise, till the screen says "off".

No smell problem if the humidifier's heating is turned off.

stevenal wrote: ↑

Wed Nov 23, 2022 2:05 pm

Warming the air with no increase in the absolute moisture content results in a decrease in relative humidity. In other words you've made the air more drying by heating it.

True.

Thanks for the knowledgeable replies. I'll have to set a "signature" with the missing data. I have a Resmed Airsense 11. And, I should have mentioned, the reservoir heat is turned off. That's where my question comes in, what if I left the hose heat on? This is where physics comes in, I guess. If the humidity of the input air decreases as it is heated, however slightly, where does the water go? It certainly does not accumulate in the hose.

I posted this as a general reply, but I thought I should post a direct reply, as well.

"Thanks for the knowledgeable reply. I'll have to set a "signature" with the missing data. I have a Resmed Airsense 11. And, I should have mentioned, the reservoir heat is turned off. That's where my question comes in, what if I left the hose heat on? This is where physics comes in, I guess. If the humidity of the input air decreases as it is heated, however slightly, where does the water go? It certainly does not accumulate in the hose.

Evaporates?

lawrencetate1 wrote: ↑

Fri Nov 25, 2022 11:21 am

Thanks for the knowledgeable replies. I'll have to set a "signature" with the missing data. I have a Resmed Airsense 11. And, I should have mentioned, the reservoir heat is turned off. That's where my question comes in, what if I left the hose heat on? This is where physics comes in, I guess. If the humidity of the input air decreases as it is heated, however slightly, where does the water go? It certainly does not accumulate in the hose.

The water goes nowhere. Relative humidity is the absolute moisture level relative to saturation. Higher temperature air can carry more moisture, so the humidity relative to saturation decreases. The numerator remains fixed, the denominator increases. It's the relative, not the absolute humidity that matters most.